Filter-press plate.



Nu. 657,628. Patented Sept. II, 1900.

.1. E. TURNEY.

FILTER PRESS PLATE.

(Application filed Mar. 16, 1900.) (N 6 II b d 6! Ail nlllll" "any J||||ii m .2 9. 4. c mmvmwmrm W'z'neggeg. .272 v6 721 072 NlTED STATESPATENT @Orrrotz.

JOHN E. TURNEY, OF LOUISVILLE, KENTUCKY, ASSIGNOR TO THE TURNEY DRIERCOMPANY, OF CHICAGO, ILLINOIS.

FlLTER- PR ESS PLATE.

SPECIFICATION forming part of Letters Patent no. 657,628, datedSeptember 11, 1900. Application filed March 16 1900, Serial No. 8,889.(No model.)

To all whom it may concern.-

Be it known that I, JOHN E. TURNEY, a subject of the Queen of GreatBritain, residing at Louisville, county of J eiferson, State ofKentucky, have invented certain new and useful Improvements inFilter-Press Plates, of which the following is a specification,reference being had to the accompanying drawings, forming a partthereof.

to In the drawings, Figure 1 is an elevation of my improved filter-pressplate having the outer covering broken away at a part of its extent todisclose the supporting wire screen and the latter also broken away at apart of I 5 its extent to disclose the grooved plate upon which itrests. Fig. 2 is a diametric section of a portion of a filter-presshaving my improved plate, showing its relation to the remainder of thecell. Fig. 3 is an enlarged detail plan of a piece of the outerfiltering element of perforated sheet metal. Fig. 4 is amany-times-magnified detail section of a piece of the sheet metal shownin Fig. 3. Fig. 5 is a detail section, about full size, through theassembled filter-plate at the grooves of the central element.

My present invention relates to plates for filter-presses of the generalcharacterin which heretofore the surface or immediate filtering elementof the plate has been some sort of textile fabric, canvas, or the like,such fabric being supported or backed by a plate or skeleton of somesort having grooves or other surface recesses into which the liquidforced by pressure through the outer filtering element passes and bywhich itis conducted to a drainage-channel, and thus passes out of thecell, of which the plate is one wall, leaving behind solid matterfilling the cell. Myimprovement relates to the character of this outeror filtering element of the plate. The canvas which has heretofore beenapplied rapidly wears out under the severe pressure which it isdesirable to employin the use of such presses 5 to filter certainclasses of material, and the cost of frequent renewals of the canvascovering of the plates is therefore a large element in the cost ofoperating the presses. I have found by experiment that perforated 5osheet metal may be used for the outer or surface covering of such plateand as the immediate filtering element with as great efficiency,

so far as the perfection of the filtering performed, as theclosest-woven textile fabric, and with greater efficiency with respectto the amount of filtration that can be effected through such plate ascompared with the fabric, and with still greater economy growing out ofthe durability of the perforated sheet metal as compared with the canvasor other textile fabric.

My improved plate comprises the central or backing element A, which ispreferably a plank grooved up and down upon, both surfaces, (except whenit is the outer wall of the end cell of the press, in which case onlyone surface is grooved,) the grooves being connected around the loweredge or margin of the plate by a cross-channel A which leads to adischarge-duct A by which the liquid is conducted out of the press. Thegrooved area of the plate A is encompassed by a shoulder A and withinsuch shoulder the openmeshed wire screen B is lodged upon such groovedsurface, the wires of the screen being preferably placed oblique to thefiltergrooves. The height of the shoulder A is sufficient only toaccommodate the thickness of the open-meshed screen B, and upon thelatter I place the perforated sheet-metal fil- 8o tering element 0,which is made of somewhatgreater diameter than the grooved area and thanthe screen B, so that it lodges upon the top of the shoulder A extendingthus be yond the periphery of the woyen-wire screen. The woven-wirescreen may be secured to the grooved plate by staples at as many pointsas may be found convenient or desirable and the perforated plate 0 maybe secured by tacks driven through it into the plank A around themargin. The plate A has a central aperture A, bounded by a shoulder Acorresponding to the shoulder A about the periphery of the plate, andthe woven-wire screen is formed with a central aperture 5 adapting it tolodge inside the shoulder A on which also the inner margin of the plateO, which is also centrally apertured, is lodged and secured in the samemanner as it is secured at the outer edge.

D is the annular wall of the cell, interposed between consecutive platesand making at 2 A es'iez ably distributed about the center and someawhat nearer the center than the periphery,

such posts being arranged to abut end to end and transmit the strain ofthe pressure which forces the material to be filtered through theelement. If, in any instance, the

accumulated contents of adjacent cells is of different character ordensity, the excess of pressure upon one side might tend to bend theplate and ultimately to break it. This 'fe'ature is common in presses ofthis class.

For the perforated plate 0, I prefer long narrow slots 0 c, &c., asshown in Fig. 3 of the drawings. These plates are made of brass or someequally-soft metal, the perforations or slots being made by pu'nchih g.This mode of perforation leaves the margins of the slots atone surfaceof the plate smooth and slightly rounded or sunken, the other surfacehaving around the margins 'of the slots fine burs 0r ragged edgesresultant from the emergence'of the punch at that side. The metal beingcomparatively soft is also affected by the stroke of the punch in such awa that the aperture is slightly greater in width at the entering sidethan at the emerging side of the punch, because the metal is apparentlyslightly stretched down into the die at the emerging side.

lies not so much in the absolute fineness of the apertures-that is tosay, it does not depend upon the apertures being fine enough to excludeor hold back all the solid matter which it is desired "or expected toretain; but

it operates as a filtering element by "causing the retention upon theentering side of the larger solid particles which accumulate across thenarrow apertures, bridging them'and'cau sing a film or Web over themwhich itself becomes a means of filtering the "subsequent liquid,holding back finer and finer particle's until there is accumulated'up'on theplate alilm su'fiiciently thick and close to permit only 'w'a-This operation is greatly faci litated by the rough edges or bursupon-one side ter to pass.

of the plate when that side is turned toward the substance to befiltered and is made the entering side. F urthe'rmore,'if thepla't-ewereplaced the other side out, the apertures being wider at that side, thefiner particles would i enter such apertures'and become wedged tight inthem, and they would eventually andv'ery quickly in practice become sothoroughly clogged that no material could pass through.

Now as a matter of fact the, value of such a perforated plate as afiltering element- For both these reasons the plate operates with verymuch better results when placed with the burred side toward thesubstance to be filtered-i. e., at the entering side-the opposite sidewhere the apertures are wider being the delivery side, thus permitting avery free delivery of anything that passes the narrower entrance of theslots.

Very considerable advantage is gained by employing for the filteringelement sheet metal having long slots instead of mere circularperforations and placing such metal sheet with its slots extending upand down in preference to horizontally. When thus formed and placed, anyparticles which may become engaged in the slots are likely to bedisengaged by the new of the water through the Stats by reason of thelength and vertical direction of the slots, and, in fact, the perforatedsheet metal, even if the perforations are thus elongated, is very liableto become clogged if the perforations extend horizontally instead ofvertically, because of the loss of the flushing effect of the waterpassing through the slots and following longitudinally along the same.

I claim- 1. A filtering-plate for a filter-press, com prising a back orcentral element superficially'channeled or grooved; an open-meshed wirescreen applied on the grooved surface of said back element; a perforatedsheetmetal -plate applied on the screen; and suitable ineans for bindingsaid elements to gether.

2. A filtering-plate for a filter-press, comprising a back or centralelement superficially channeled or grooved; an open-meshed wire screenapplied upon the grooved surface; a sheet-me tal plate havingperforations in the form of long, narrow slots,-applied upon the Wirescreen; and suitable means for binding said "elements together.

3. A filtering-plate for a filter-press, comprising a back or centralelement superficially grooved; an open-meshed wire screen appl'ieduponthe grooved surface; a sheetmetal plate perforated with 'fine slotswhose margins-are bu rred or roughened, such plates being applied uponthe Woven-wire screen with its burred or roughened surface 'out Ward.

t. A filtering-plate for a filter-press, comprising a back or centralelement having'vertieal parallel channels or grooves and suitable meansfor draining the same; an openmeshed wire screen applied upon thegrooved surface with its wires in both directions obliqueto the verticalgrooves; a sheet-metal plateperforated with long fi'ne slots appliedupon the open-meshed screen; and suitable means 'fo'r securing saidseveral elements together. I

5. A filtering-plate for a filtering-press, comprising a back'orcentral'e'lement having up and-"down drainage-channels; an openmeshedwire-screen applied upon such central element and its surface coveringconstiof two Witnesses, this 14th day of March, A. D. tuting thefiltering element, consisting of 1900. sheet metal perforated with long,fine slots,

and applied with its slots extending up and JOHN TURNEY' 5 down. Inpresence of- In testimony whereof I have hereunto set CHAS. S. BURTON,my hand at Chicago, Illinois, in the presence ADNA H. BOWEN, Jr.

